The construction and operation of hobs and rotary cutting machines are well known in the relevant art. A typical construction for a hob is disclosed in U.S. Pat. No. 3,175,275 to Zorn. Zorn's hob comprises a substantially cylindrical main tool body having transverse recesses in its external surface substantially extending along the entire axial length of the tool body. Cutter bars or blades are inserted into the recesses with the blades extending from one end of the recesses to the other along the axis of the body. In one embodiment of Zorn's hob, a thin layer of a very high solidity compound is provided between end surfaces of the blades and possibly end surfaces of the body for compensating for any inaccuracies in size and alignment between those surfaces.
Yet another hob construction is disclosed in U.S. Pat. No. 4,023,246 to Haug et al.. Haug's hob also includes a substantially cylindrical main body having axially extending recesses or slots for accepting cutter blades. An adhesive is used to retain the inserted blades within the slots.
The above-discussed hob constructions, which are typical of the prior art, require formation of recesses or slots in the main tool body axially extending substantially along the entire length of the hob. This recess formation can be quite complicated and time consuming. The recesses must be precisely formed in the main body in order to position the cutter blades properly for machining gears and the like as intended. Formation of the recesses, therefore, can be costly in both time and labor.
The present invention is intended to solve the foregoing problems presented by the prior art, and is a significant improvement over those constructions.